Rubber-modified aromatic vinyl copolymer resins such as an acrylonitrile-butadiene-styrene copolymer resin (ABS resin) can have excellent mechanical properties, processability, and appearance characteristics and thus are widely used as an interior/exterior material for electric/electronic products, an interior/exterior material for automobiles, and an exterior material for buildings.
Since such a rubber-modified aromatic vinyl copolymer resin can suffer from deterioration in properties such as discoloration when used for a long time, research has been conducted to improve weather resistance (discoloration resistance) of the resin. Examples of a method for improving weather resistance include use of an acrylate rubber polymer as a rubber polymer of a rubber-modified aromatic vinyl copolymer resin, addition of a weathering stabilizer, and the like.
However, as the content of the acrylate rubber polymer increases, the acrylate-based rubber-modified aromatic vinyl copolymer resin can have lower impact resistance and the cost burden increases, causing reduction in economic efficiency. In addition, the weatherability stabilizer can cause deterioration in appearance characteristics and mechanical properties due to gas emission when used in excess, making increase in usage of the weatherability stabilizer difficult.
Further, a thermoplastic resin is often required to have antibacterial properties (activity) when used in the manufacture of a molded article that directly or indirectly contacts the human body.
Therefore, there is a need for a thermoplastic resin composition which has good properties in terms of weather resistance and antibacterial properties (activity) without deterioration in mechanical properties such as impact resistance and appearance characteristics while reducing cost burden.